The pattern and genetics of pediatric extrinsic asthma risk factors in polluted environment.

AIM: The aim of the present study is to determine the effect of polluted environment on extrinsic of asthma and allergic diseases among school children.

DESIGN

This is case and control study.

SETTING

The study was carried out among school children living and attending the school in industrial and residential area during the period of October 2004 and June 2005.

SUBJECTS: The study based on age, sex, and ethnicity of 716 cases (with asthma) and 716 controls (without asthma) school children living in both urban and in industrial polluted with oil refinery and chemical pollutant.

METHODS

The International study of asthma and allergies in childhood (ISAAC) and some additional questionnaires were used to collect the data of the school children. The questionnaire included information about: socio-demographic characteristics; respiratory symptoms; associated respiratory illness; family history of allergic diseases among first-degree relatives of asthmatic children; behavioural factors which could be additive to asthma. Univariate and multivariate statistical analyses were performed.

RESULTS

The proportion of children in the asthmatic group who reported symptoms was significantly higher than in non-asthmatic group (<0.0001). The asthmatic group reported that 47.5% morning time breathlessness, shortness of breath (61.4%), wheeze after exercise (65.4%), phlegm (45.3%) and chronic cough (42.2%). Male asthmatics had a average age at onset of symptoms of 6.9% (+/-4.8%) years compared with female asthmatics who had higher age at onset of symptoms, 7.6 (+/-5.9). Male asthmatics also had longer duration of symptoms (7.5 +/- 4.9 in males and 6.4 +/- 4.6 years in females). Significantly odds ratios were found higher in asthmatic compared to controls for pneumonia, bronchitis, atopy (allergic rhinitis and atopic dermatitis), sinusitis, croup, parental asthmas, parental atopy including parental allergic rhinitis, atopic dermatitis and parental smoking (p < 0.0001). The logistic regression model showed that shortness of breath, bronchitis, pneumonia, sinusitis, parental asthma, allergic rhinitis, atopic dermatitis, croup, pets ownership and parental smoking were significant risk factors for asthma

CONCLUSION

The present study provides some evidence that exposure to outdoor air pollutants increases the risk of childhood asthma and allergic diseases in school children. The results are consistent with the hypothesis that long term exposure to NOx and CO levels suggests that emissions from photochemical air pollution and oil refinery contributes to adverse health effects in Qatar.